The mod, which can be downloaded by heading to the Steam Workshop (currently most easily accessed by going to the Skyrim game page in your Steam client, scrolling down to the big, blue bar labeled Steam Workshop, and giving it a gentle, tender, even sensuous click), adds Portal 2's Space Core to a burnt out house near Whiterun. You can pick it up and make it talk about space things. Only space things.

The mod is a collaborative effort between Valve and Bethesda to help promote the launch of the Steam Workshop, which lets users showcase their home-brewed mods. It's titled Fall of the Space Core, Vol. 1, so perhaps more are on the way.